FIELD OF THE INVENTION
The present invention relates generally to tools for gripping a hardware element, and more particularly to an open-end wrench for gripping a hardware element such as a nut or the head of a bolt, which each typically have a hexagonal configuration, in a manner allowing the wrench to be used for rotational driving of the hardware element in either direction without requiring the wrench to be periodically removed, repositioned, and replaced on the hardware element in order to continue rotation of the hardware element in the desired direction.
Although a wide variety of hand tools are available for just about any conceivable application, there continues to be a demand for improved tools as well as tools offering increased versatility or enhanced ease of use. Nowhere has this been mode evident than in the area of wrenches used to rotate hardware elements such as nuts or the heads of bolts. A wide variety of basic tools has long been available for performing this function, including everything from basic open-end wrenches, box end wrenches, and crescent wrenches to sockets and socket wrenches.
While the more basic wrenches such as open-end wrenches, box end wrenches, and crescent wrenches offer the advantages of being simple, inexpensive, and relatively compact, there is little doubt that sockets and socket wrenches have found favor in use due to the fact that they have a ratcheting mechanism. A ratcheting mechanism allows the socket to be placed on the nut or the head of the bolt only once, with the handle of the socket wrench then being ratcheted back and forth to drive the nut or bolt. Socket sets are more expensive, and have the disadvantage that they may not be used to drive a nut onto an extended length threaded stud, since the socket must be able to fit over both the nut and the portion of the stud that the nut has been screwed onto.
More recently, a number of different alternative tools offering the advantages of a ratcheting mechanism in the embodiment of a simple hand tool have emerged. Such tools include a variety of novelty wrenches professing to be "universal" wrenches which adapt to a range of different size nuts or bolt heads. Such tools generally have a V-shaped receiving member, with an additional member biasing the hexagonal nut or bolt head into the V-shaped receiving member when the handle of the wrench is turned in the proper direction. The mechanism used in such "universal" wrenches is not a true ratcheting mechanism since the angle of the handle with respect to the V-shaped receiving member varies as the tools is used to retain the nut or bolt head within the jaws of the V-shaped receiving member.
In a variation of this concept, one wrench presently known in the art uses a gear mechanism to close jaws similar to those of a crescent wrench as the handle of the wrench is rotated with respect to one side of the jaws. Again, this wrench does not have a true ratcheting mechanism, since the angle of the handle of the tool must be changed twice in each stroke of the tool. This is not a desired operational characteristic, and as might be expected, such tools have never enjoyed widespread popularity.
Another variation on this theme uses a box-end with a driving handle mounted at a ninety degree angle with respect to the box-end jaws. This tool uses a shaft which is rotated to drive a nut or bolt head. Another variation of this tool uses serrated jaws such as those of a pliers instead of the box-end jaws. These tools all have the marked disadvantage that they must be rotated rather than operated by moving the handle from side to side repeatedly. A socket wrench offers the same mode of operation while having a better gripping arrangement for contacting the nut or bolt head.
In fact, the only ratcheting type hand wrench which has ever enjoyed a substantial degree of popularity is the wrench having a built-in ratcheting mechanism which allows a rotating box-end to rotate in a single direction only. Such ratcheting wrenches offer two principal disadvantages. First, by their nature they are box-end wrenches, and thus cannot be constructed as open end wrenches. In addition, while such tools operate quite well, they have a relatively high degree of mechanical complexity, and as such are expensive to manufacture. As such, they have been limited in their use by their necessarily high selling price.
It is accordingly the primary objective of the present invention that a hand wrench be provided which offers the simplicity and advantages of a conventional open-end wrench, but with a ratcheting mode of operation. It is a related objective of the present invention that the ratcheting mechanism of the wrench function in a manner which is independent from the angular position of the handle of the wrench, thereby not depending on a variation of this angular position to grip or release a nut or bolt head as do so-called "universal" wrenches. It is a related objective of the present invention that the ratcheting mechanism of the wrench be of relatively simple mechanical construction, requiring a minimal number of mechanical components for the simplest possible construction.
It is a further objective of the present invention that the mechanical components of the wrench be operable in a manner not requiring a great amount of precise machining of the components to facilitate the ratcheting operation of the wrench. It is still another objective of the present invention that the ratcheting mechanism of the wrench function automatically, without requiring any special procedure to grip a nut or bolt head when the wrench is turned in one direction and to release the nut or bolt head when the wrench is turned in the opposite direction. It is yet another objective of the present invention that the wrench be operable to turn a nut or bolt head in either direction by merely turning the wrench over, rather than requiring any adjustment to the wrench be made to facilitate changing the direction of rotation.
The wrench of the present invention must also be of a mechanical construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout the operating lifetime of the wrench. In order to enhance the market appeal of the wrench of the present invention, it should also be of relatively inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the present invention be achieved without incurring any substantial relative disadvantage.